1. Field of the Invention
This invention relates to agricultural irrigation and more particularly to moving an agricultural irrigation system and maintaining it in alignment as it is moved.
2. Description of the Prior Art
Irrigation systems which move in a circle around a pivot are well known and commercially available on the market. Also, there are many arrangements for driving the systems and maintaining them in alignment as they are driven. There has been previously patented a system where a taut line was stretched from one end of the system to the other and the individual vehicles prevented from moving by dropping a block into a mechanical movement system, Boone U.S. Pat. No. 3,302,656.
Previous systems have been operated by hydraulics and in such systems, traditionally, a single line extends to each vehicle and two valves are required on each vehicle. One of these valves throttles the fluid into the power cylinder for alignment purposes and the other valve switches the fluid under pressure to one side or the other of the piston.